At least 18 gunshots were fired outside Bethlehem's Puerto Rican social club during a fatal 2012 gun battle that authorities have labeled one of the Lehigh Valley's worst, according to testimony Thursday.

Investigators scouring the South Side shooting scene documented 18 spent bullet casings, said city detective Douglas Nothstein, who helped process the evidence. All were from .40- and .45-caliber rounds, he said — the same caliber as the two handguns that police seized after the firefight that killed one woman and injured five other people.

Prosecution witnesses have tied the two guns to Javier Rivera-Alvarado and Rene Figueroa, the defendants in a trial that reached its sixth day of testimony in Northampton County Court. They are charged with a slew of felonies in the shootout, with Figueroa facing the death penalty if convicted of murdering 23-year-old Yolanda Morales of Bethlehem, who was gunned down early that morning.

But whether the spent casings represent an accurate estimate of the gunplay remained a point of contention. Rene Figueroa's lawyer, Jack McMahon, noted that some firearms don't eject their shells, and could have been used during the battle without leaving casings as a result.

"A person could shoot, at a scene such as this, a revolver and there would be no casings?" McMahon asked Nothstein.

"Correct," the detective agreed.

A jury must decide whether Rivera-Alvarado and Figueroa were the aggressors in the melee near the Puerto Rican Beneficial Society on Dec. 2, 2012. Their attorneys insist that their clients, who also suffered gunshot wounds, are actually the victims.

The .45-caliber handgun was discovered by police hidden in a garbage can in the East Third Street club, where the injured Figueroa fled after the shooting.

Prosecutors' star witness, Orialis Figueroa, has testified he took the .40-caliber handgun off of Rivera-Alvarado after knocking him unconscious with a baseball bat in self-defense, though his account is disputed by defense lawyer Edward Andres, who says his client never had a gun.

Both firearms were empty when police recovered them. The .45-caliber gun could hold up to nine rounds, Nothstein said; six casings from a .45 were found at the scene. The .40-caliber gun held up to 15 rounds; 12 casings from a .40 were found, he said.

Nothstein testified for the entire day, walking jurors photograph by photograph through the casings, blood splotches, bullet fragments and other pieces of evidence that police marked as they combed for clues. He often stood in court before a white-board drawing of East Third Street, using different color inks to highlight the various items and where they were found.

The shooting occurred after a minor incident in the club spilled into the street, according to testimony. It created a crime scene so complicated that investigators had to draw diagrams — like the one Nothstein used before the jury — to make sense of what happened.

Though Thursday's evidence was dry and matter of fact, both sides seized upon details of it that they believe help make their cases. First Deputy District Attorney Terence Houck showed jurors a dark photograph of the scene to bolster his claim that it was difficult for witnesses to make out exactly what was happening in the firefight.

McMahon countered by displaying other, lighter, photos for the jury, saying they showed that visibility was fine.

The defense also highlighted that police did not search all of the cars parked in the area of the shooting, arguing that police may have missed evidence inside them.

And the attorneys noted that testing of Morales' shirt uncovered no gunpowder traces to show she was shot at close range — even though Orialis Figueroa has testified that he saw Rene Figueroa (who is of no relation) grab her, spin her around and fire a fatal shot into her back.

The defense attorneys charge that it was Orialis Figueroa, of Easton, who started the melee and whose reckless gunfire killed Morales. McMahon has mocked Orialis Figueroa to the jury as "our local hero," saying the story that he and his relatives told police is a "total fabrication."

This week and last week, at least five relatives of Orialis Figueroa have offered testimony backing his account to the jury: that the shootout was sparked when Rivera-Alvarado sneaked up behind him and placed a gun to the back of his head.

Orialis Figueroa was shot in both legs. His brother, Angel Figueroa, was paralyzed from a bullet. Another relative, Luis Rivera, was shot in the knee.

The defendants were also hospitalized. Rivera-Alvarado was shot in the leg and knocked out by the blow from the bat. Rene Figueroa had gunshot wounds to his stomach, elbow, wrist and buttocks, police have said.

Rivera-Alvarado, 40, and Rene Figueroa, 34, both of Allentown, face allegations that include attempted murder, conspiracy and aggravated assault, though only Figueroa is charged with homicide.